PEACE RIVER MANASOTA REGIONAL WATER SUPPLY AUTHORITY BOARD OF DIRECTORS MEETING December 21, 2011 CONSENT AGENDA ITEM 9

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1 PEACE RIVER MANASOTA REGIONAL WATER SUPPLY AUTHORITY BOARD OF DIRECTORS MEETING December 21, 2011 CONSENT AGENDA ITEM 9 Work Order Preparation of 2011 HBMP Comprehensive Summary Report to Agreement for General Environmental Services with Atkins North America, Inc. Recommended Action - Motion to approve and authority Executive Director to execute Work Order Preparation of 2011 HBMP Comprehensive Summary Report to Agreement for General Environmental Services dated February 2, 2011 with Atkins North America, Inc. The Peace River Facility Water Use Permit (W.U.P.) issued by the Southwest Florida Water Management District (SWFWMD) requires a Hydrobiological Monitoring Program (HBMP) be implemented to monitor the Lower Peace River / Upper Charlotte Harbor. The HBMP has been ongoing since 1976 for the purpose of monitoring the lower river and estuary to ensure no significant adverse ecological impacts result from withdrawals at the Peace River Facility. As part of the HBMP, every five years the Authority is required to complete a Comprehensive Summary Report for the HBMP program. This report is an interpretive work that analyzes HBMP historical data; examining long term trends, variables and relationships between ecological patterns and fresh water inflows. Staff recommends the 2011 HBMP Comprehensive Summary Report be completed through the Authority s existing Agreement for General Environmental Services with Atkins. Atkins (formerly PBS&J) has been the lead consultant on the HBMP project for many years and their staff has a unique knowledge of the Peace River system and a thorough understanding of the data collected. Atkins proposal is attached and totals ($149,934 which is a reduction of approximately $3,000 from the 2006 Comprehensive Summary Report, also completed by PBS&J (now Atkins). Funding for this project is available in the FY 2012 budget under the HBMP line item.

2 GENERAL ENVIRONMENTAL SERVICES WORK ORDER No Preparation of 2011 HBMP Comprehensive Summary Report INTRODUCTION This Work Order No Preparation of 2011 HBMP Comprehensive Summary Report is conducted pursuant to the Agreement for General Environmental Services entered into on February 2, 2011, between the Peace River Manasota Regional Water Supply Authority (Authority) and Atkins North America Inc. (Consultant) (formerly PBS&J). SCOPE OF WORK Work will be conducted as outlined below and in the attached December 8, 2011 correspondence from Atkins. Task 1. Gather and convert data into SAS data sets, prepare an executive summary and prepare report introduction and summary - $14,688. Task 2. Provide summaries of recent Peace River Watershed/Charlotte Harbor Reports and primary conclusions - $25,100. Task 3. Provide status and trends in regional rainfall and flows, Facility withdrawals and HBMP water quality indicators - $35,608. Task 4. Assessment of long-term trends and changes in water quality in the Peace River Watershed, influences of increasing conductivity, and salinity/flow relationships at continuous recorders - $44,792. Task 5. Evaluation of existing withdrawal schedule - $9,284. Task 6. Evaluation of adverse impacts and appropriate indicators $624. Task 7. Proposed monitoring design modifications - $3,278. Task 8. Prepare draft outline and meet with Authority staff to finalize Report outline, prepare draft document for review by Authority staff, review comments and implement changes as necessary, provide final ATKINS internal QA/QC review, prepare final linked CD version of the completed report, prepare final printed copy and CD versions of completed report. Report to follow attached December 2, 2011 outline - $16,560.

3 DELIVERABLES 1. Monthly invoices. 2. Five draft copies of the HBMP 2011 Comprehensive Summary Report 3. A hard copy of the report, with an attached CD containing full copy of the entire HBMP 2011 Comprehensive Summary Report and all associated data files will be submitted to the District for the file-of-record and up to an additional 10 CD copies and three hard copies provided to the Authority. COMPENSATION The Authority agrees to compensate Consultant in accordance with the task limits listed in the table below, the total of which will not exceed total cost of $149,934. Consultant s invoices will be submitted monthly showing total authorized cost, total for current invoice, total for prior invoices and balance remaining. Appropriate documentation justifying reimbursable expenses and daily labor will also be provided as supporting documentation to the Consultant s invoices to the Authority. Task # Task General Description Authorized limit Lump Sum (LS) or Time and Materials (T&M) 1 Data Gathering & Conversion $14,688 LS 2 Provide Summaries of Recent Reports $25,100 LS 3 Data Status and Trends $35,608 LS 4 Assessment of Long-Term Changes $44,792 LS 5 Evaluation of Withdrawal Schedule $9,284 LS 6 Evaluation of Impacts $624 LS 7 Proposed Monitoring Design Changes $3,278 LS 8 Draft and Final Report Preparation $16560 LS $149,934 SCHEDULE Consultant services will commence upon execution of this Work Order. The schedule for completion and submittal of the final shall be as identified in the Water Use Permit, or as otherwise agreed upon with SWFWMD review staff. IN WITNESS WHEREOF, the parties hereto have executed this Work Order as of the day and year last written below. PEACE RIVER MANASOTA REGIONAL WATER SUPPLY AUTHORITY

4 Patrick J. Lehman, P.E. Executive Director Date ATKINS NORTH AMERICA INC. Pete Putman Vice President Date

5 MEMORANDUM DATE: December 21, 2011 TO: THRU: FROM: Patrick Lehman P.E., Executive Director Mike Coates, P.G., Water Resources Division Director Samuel S. Stone, Environmental Affairs Coordinator RE: Authorization for Atkins (formerly PBS&J) to Provide the Hydrobiological Monitoring Program 2011 Comprehensive Summary Report Summary & Recommendation: Staff recommends approval of Work Order under the General Environmental Services Agreement with Atkins (formerly PBS&J) for development of the HBMP 2011 Comprehensive Summary Report at a cost not to exceed $149,934. This report is required under the Peace River Facility Water Use Permit to be developed and submitted to SWFWMD every 5 years. The proposed cost from Atkins is a reduction of approximately $3,000 from the 2006 Comprehensive Summary Report. Funding for this project is available in the FY 2012 budget under the HBMP line item. Background: The Peace River Facility Water Use Permit (W.U.P.) issued by the Southwest Florida Water Management District (WMD) requires that a Hydrobiological Monitoring Program (HBMP) be implemented to monitor the Lower Peace River / Upper Charlotte Harbor. The HBMP has been an on going program since The purpose of the HBMP is to monitor the lower river and estuary to ensure that no significant adverse ecological impacts result from withdrawals at the Peace River Facility. Although the HBMP has been ongoing since 1976, the program was expanded during the 1996 Water Use Permitting process. This expanded program includes a multi-tiered analytical and reporting system based on five year cycles. During each five-year cycle the Authority is required to submit a data report annually, and a summary report every five years to SWFWMD. This cycle then repeats through the rest of the permit period. Discussion: The HBMP 2011 Comprehensive Summary Report is an interpretative report that analyzes all HBMP data through 2011, examining long term trends, variables and relationships between ecological patterns and fresh water inflows. In this report the HBMP program design will be

6 2011 HBMP Annual Comprehensive Summary Report Page 2 evaluated to determine if changes are needed. The report will also evaluate the effectiveness of the withdrawal schedule for preventing adverse impacts, and finally will evaluate the presence or absence of adverse ecological impacts to the downstream estuary. Atkins (formerly PBS&J) has been the lead consultant on the HBMP project for many years, and has a unique knowledge of the Peace River system, and a thorough understanding of the data collected. As such the Authority requested and received a scope and fee proposal from Atkins (formerly PBS&J) for development of the 2011 HBMP summary report (see attached proposal dated 12/08/11). Authority staff has reviewed the scope of work and found the proposal to be complete, and sufficient to meet the W.U.P. requirements. Proposed cost for the 2011 Comprehensive Summary Report is $149, which represents a cost reduction of approximately $3,000 from the 2006 Comprehensive Summary Report. Work Order and the December 8, 2011 proposal from Atkins, and the proposed outline of the report HBMP 2011 Comprehensive Summary Report are attached.

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9 Summary Peace River Manasota Regional Water Supply Authority HBMP 2011 Comprehensive Summary Report (Revised Scope of Work - December 2, 2011) This introductory section will provide a ten to fifteen page summary of the major findings, conclusions and recommendations of each of the following chapters. In addition, as appropriate, bullet summaries of major conclusions will be presented at the end of each chapter. Chapter 1 Introduction The purpose of this section will be to provide a brief overview of the general permit history and conditions, the study elements within the HBMP, and summarize the report s organization and primary objectives. 1. Purpose of Report. 2. Summary of Facility s permit history and conditions (updated information from that included in previous Annual Data Reports and the 2006 HBMP Comprehensive Summary Report). Using available aerials, a visual history and timeline will be included. 3. Provide updated discussion of long-term water demand and supply projection needs based on information presented in Authority and SWFWMD reports and studies. This would include brief discussions of Authority s Master Water Supply Planning, and ongoing feasibility and future alternative source studies. The section will also include tables and appropriate graphics summarizing historic and projected Facility demands. 4. Summarize HBMP program elements (update of information in 2006 HBMP Comprehensive Summary Report and both the 2010 and 2011Annual Data Reports). a. Overview of historic chronology of HBMP water quality and biological monitoring programs and updated summary table of program elements changes and/or deletions, b. Summary of current HBMP monitoring programs Moving, isohaline based station monitoring Fixed stations monitoring program elements USGS and Authority continuous recorders data collections

10 5. Outline the conceptual HBMP process for evaluating key water quality and biological estuarine components, and assessing potential adverse estuarine impacts from current permitted withdrawals. 6. Summary overview of report organization and primary objectives. Chapter 2 Summaries of Recent HBMP Reports and Primary Conclusions The 2002 Peace River Comprehensive Summary Report (finalized in 2004) provided brief overviews of major studies related to the lower Peace River/upper Charlotte Harbor estuary system completed between 1996 and These included: 1. Summary of Historical Information Relevant to the Hydrobiological Monitoring of the Lower Peace River and Upper Charlotte Harbor Estuarine System (PBS&J Inc. July 1999) HBMP Midterm Interpretive Report (PBS&J Inc. February 2002) HBMP Annual Data Report (PBS&J Inc. August 2003) 4. Morphometric Habitat Analysis of the Lower Peace River (PBS&J Inc. January 2000) 5. Regression Analysis of Salinity-Stream Flow Relationships in the Lower Peace River / Upper Charlotte Harbor Estuary (Janicki Environmental Inc. March 2002) 6. HBMP Supplemental Analysis (PBS&J Inc. June 2002) 7. Peace River Benthic Macroinvertebrate and Mollusk Indicators (Mote Marine Laboratory July 2001) 8. An Assessment of the Effects of Fresh Water Inflow on Fish and Invertebrate Habitat use in the Peace River and Shell Creek Estuaries (University of South Florida College of Marine Science September 2002). 9. An Analysis of Vegetation-Salinity Relationships in Tidal Rivers on the Coast of West Central Florida (SWFWMD, Draft 2002) 10. Development of GIS-Based Maps to Determine the Status and Trends of Oligohaline Vegetation in the Tidal Peace and Myakka Rivers (Florida Marine Research Institute, 1998) The 2006 Peace River Comprehensive Summary Report (finalized in 2009) provided additional brief overviews of major studies related to the lower Peace River/upper Charlotte Harbor estuary system completed between 2002 and These included: 1. Upper Peace River Analysis of Minimum Flows and Levels (SWFWMD 2002) 2. Predicted Change in Hydrologic Conditions along the Upper Peace River due to a Reduction in Ground-Water Withdrawals (Basso 2003) 3. Long-term variation in Rainfall and its effect on Peace River Flow in West-Central Florida (Basso 2003) 4. An Evaluation of Stream Flow Loss during Low Flow Conditions in the Upper Peace River (Basso 2004) HBMP Annual Data Report (PBS&J August 2004) 6. Florida River Flow Patterns and the Atlantic Multidecadal Oscillation (Kelly 2004) 7. Shell Creek and Prairie Creek Watersheds Management Plan (SWFWMD 2004)

11 8. Proposed Minimum Flows and Levels for the Middle Segment of the Peace River, from Zolfo Springs to Arcadia (SWFWMD 2005) HBMP Annual Data Report (PBS&J May 2005) HBMP Annual Data Report (PBS&J August 2006) 11. Assessment of Potential Shell Creek Impacts Resulting from Changes in City of Punta Gorda Facility Withdrawals (PBS&J 2006) 12. Peace River Cumulative Impact Study (PBS&J January 2007) HBMP Annual Data Report (PBS&J Expected May 2007) 14. Lower Peace River Initial Draft Analysis of Minimum Flows and Levels (SWFWMD 2007) These summaries presented in previous HBMP Comprehensive Summary Reports will be included for historic reference in an appendix at the end of this 2011 document. Chapter 2 will provide brief (3-5 page) overviews of major studies and reports related to the Peace River watershed, lower Peace River and upper Charlotte Harbor that have been finalized since the previous Comprehensive Summary Reports. The primary objective and focus of this chapter will be to provide concise overviews of the purpose and major conclusions of each of these studies. Summaries will be included for the following reports/studies (and other documents as they are identified): 1. Final Southern Water Use Caution Area Recovery Strategy (March 2006) HBMP Annual Data Report (PBS&J May 2008) 3. Revised Draft - Proposed Minimum Flows and Levels for the Lower Peace River and Shell Creek (SWFWMD August CHNEP Comprehensive Management Plan CHNEP Environmental Indicators Report HBMP Annual Data Report (PBS&J May 2009) HBMP Annual Data Report (PBS&J May 2010) HBMP Annual Data Report (Atkins June 2011) 9. Final - Proposed Minimum Flows and Levels for the Lower Peace River and Shell Creek (SWFWMD April 2010) SWFWMD Regional Water Supply Plan Southern Planning Region (SWFWMD July 2011) 11. Update of Florida Department of Environmental Regulation determination of impaired waters in the Peace River watershed. 12. Summary of EPA proposed numeric water quality criteria for Peace River watershed freshwater and estuarine systems HBMP Annual Data Report (Atkins expected May 2012) 14. Draft 2012 Water Resource Development Work Plan (SWFWMD 2011)

12 Chapter 3 Status and Trends in Regional Rainfall and Flows, and Facility Withdrawals The primary objective of this chapter will be to provide updated graphical plots and trend tests of rainfall and flows in the Peace and Myakka River Watersheds. Analyses and comparisons will be conducted over specific intervals including: 1. The long-term period of record for each USGS gaging site 2. The period of HBMP monitoring ( ) 3. The three recent phases ( , , ) of the proposed Atlantic Multidecadal Oscillation (AMO) Summary results of these analyses and comparisons will be provided both graphically and as summary tables. Recent and historical unusual occurrences (such as extended droughts and unusually wet intervals) will be documented and compared to the long-term average statistical characteristics at each gaging location. Rainfall four long-term NOAA gages will be used to determine recent and historic natural variability in rainfall patterns within the Peace and Myakka River watersheds from long-term available data at four monitoring sites. Monthly total rainfall will be plotted over time and as the cumulative difference from the long-term mean in order to assess potential trends. Upper Watershed (Bartow) Mid Watershed (Arcadia) Lower Watershed (Punta Gorda) Myakka near Sarasota Flows data from the long-term U.S. Geological Survey (USGS) network of flow monitoring gaging sites in the Peace and Myakka watersheds will be used to evaluate and compare recent and historic patterns in flows. Peace River Watershed Peace River at Bartow Peace River at Fort Meade Payne Creek near Bowling Green Peace River at Zolfo Springs Charlie Creek near Gardner Peace River at Arcadia Joshua Creek at Nocatee Horse Creek near Arcadia Prairie Creek near Fort Ogden Shell Creek near Punta Gorda Sum of Peace at Arcadia, Horse Creek and Joshua Creek Sum of Peace at Arcadia, Horse Creek, Joshua Creek and Shell Creek

13 Myakka River Watershed Myakka River near Sarasota Time Series Analyses of Variability in USGS Gaged Flows time-series plots and Seasonal Kendall Tau trend test will be run for the period of record and the period at each gauging site for a variety of statistical flow characteristics in order to determine potential longterm changes in flow patterns from both natural and anthropogenic influences. P0 Percentile the minimum or lowest monthly value P10 Percentile low flow value that was exceeded ninety percent of the time P25 Percentile low flow value that was exceeded twenty-five percent of the time P50 Percentile or median value, half of the monthly values were both greater and less P75 Percentile low flow value that was exceeded Seventy-five percent of the time P90 Percentile high flow value that was exceeded only ten percent of the time P100 Percentile the maximum or highest monthly value Mean- this average monthly value is usually above the median when evaluating flow data In addition, comparisons among the USGS gaging sites (and sums) above will be determined using a series of Seasonal Kendall Tau trend test using standardized five-year intervals, such that the number of intervals tested for each gage differed depending on the length of the gage s particular period-of-record. Comparative differences will be determined for three different flow statistics for each gage site. The low flow P10 Percentile, which is exceeded ninety percent of the time The median flow P50 Percentile, which is greater and less that half the monthly flows The high flow P90 Percentile, which is exceeded only ten percent of the time Seasonal Differences Trend tests of will also be conducted to determine long-term patterns in mean and median flows for three seasons (July-October, November-February, and March- June). Differences in Flows among AMO Periods The same three flow percentiles will be used to determine potential differences in flows at the selected USGS gages for the , , and time periods. Rainfall/flow interactions cumulative single mass plots of rainfall over time and flows over time, as well as cumulative rainfall versus flow plots (double mass) will be used to assess both historic natural and anthropogenic changes in flows that have historically occurred within the Peace River Watershed. Analyses will be conducted to determine and depict both seasonal and long-term differences between wet & dry periods. Withdrawals historical changes in withdrawal patterns will be evaluated relative to freshwater flows at Arcadia, at the Peace River Facility, and at the US 41 Bridge. A number of alternative

14 graphical methods will be used to show both the timing and relative seasonal magnitude of facility withdrawals. Plot withdrawals versus time Plot withdrawals as percent of flow versus time Plot withdrawals versus flow Sum of Peace at Arcadia, Horse Creek and Joshua Creek before and after withdrawals Sum of Peace at Arcadia, Horse Creek, Joshua Creek and Shell Creek before and after withdrawals Chapter 4 Status and Trends of Hydrobiological Water Quality Indicators in the Lower Peace River/Upper Charlotte Harbor Estuarine System Fixed HBMP Water Quality Monitoring Sites long-term patterns, potentially statistically significant trends, and differences relative to flow conditions will be evaluated at the five water quality locations along the HBMP monitoring transect (River Kilometers -2.4, 6.6, 15.5, 23.6 and 30.4) for a number of key selected surface water quality variables. Salinity/Conductivity Color TSS Silica N2/3 NH3/4 TKN OP Chlorophyll a Presented graphical and statistical analyses will include: a. Time series plots for each of these selected water quality parameters will be presented for each of the five monitoring locations. Statistical methods will be utilized to test for differences between the two periods ( and ???) of available data. b. Univariate plots will be used to compare and contrast each water quality parameter by river kilometer under seven differing levels of Peace River at Arcadia based flows. All flows Very Low (0 90 cfs) = less than Q10 Low ( cfs) = Q10 to Q25 Normal Low ( cfs) = Q25 to Q50 Normal High ( cfs) = Q50 to Q75 High ( cfs) = Q75 to Q90 Very High (above 2100 cfs) = greater than Q90

15 c. Plots and statistical correlations will be used to analyze surface values for each site versus each of the above flow categories. Moving Isohaline HBMP Monitoring Locations - key selected water quality variables at the monthly moving stations will be used to evaluate long-term patterns, potentially statistically significant trends, and differences relative to flow conditions at the four isohaline based salinity monitoring locations along the HBMP monitoring transect (0, 6, 16 and 20 psu) for the same key selected surface water quality variables used above. Isohaline Location (River Kilometer) Color TSS Silica N2/3 NH3/4 TKN OP Chlorophyll a Presented graphical and statistical analyses will include: a. Time series plots for each of these selected water quality parameters will be presented for each of the four moving isohaline monitoring locations. Statistical methods will be utilized to test for patterns and trends over the long-term interval. b. Univariate plots will be used to compare and contrast each water quality parameter by isohaline under seven differing levels of Peace River flows, based on the combined long-term average total gaged flows upstream of the Facility (Peace at Arcadia, Horse Creek and Joshua Creek). All flows Very Low = less than Q10 Low = Q10 to Q25 Normal Low = Q25 to Q50 Normal High = Q50 to Q75 High = Q75 to Q90 Very High = greater than Q90 Chapter 5 Assessment of the influence of Long-term and Periodic change in Upstream Watershed Water Quality and Potential Influences of Facility Water Supply The 2007 Peace River Cumulative Impact Study (CIS) identified anthropogenic derived changes in water quality in the Peace River Watershed. More recently, the Authority and its HBMP monitoring program have identified changes in water linked to the permitted closure of

16 phosphate stacks in the Whidden Creek subbasin (2010 HBMP Data Report). The primary objective of this chapter will be to determine, summarize and evaluate potential water quality changes and trends in the Peace River basin watershed upstream of the Facility, and assess possible influence such changes may have on either treatment or storage of water in the reservoirs (nutrient changes leading to increased potential for algal blooms). Appropriate available period-of-record data will be gathered from the following sources to assess long-term patterns (plots) and changes (trends). 1. USGS ambient monitoring programs 2. District background monitoring program 3. FDEP STORET 4. Recent Authority watershed monitoring FDEP and District staff will be consulted in order to determine known activities and programs that might be expected to have both positive and potential negative influences on further upstream water quality. Projects will include those associated with the Winter Haven Chain of Lakes, Lake Hancock, and ongoing Peace Creek Restoration activities, as well as future phosphate facility closures in the upper watershed. Chapter 6 Influences of Increasing Conductivity in the Lower Peace River Watershed The 2007 Peace River Cumulative Impact Study (CIS) and the 2006 HBMP Comprehensive Summary Report identified anthropogenic increasing trends in the dry season conductivity of many of the major tributaries in the lower Peace River Watershed. The primary objective of this chapter will be to further evaluate these trends beyond the period covered by these reports (2004, and 2006 respectively) and determine the duration and potential magnitude such increases may be having on the dry season conductivity of lower Peace River immediately upstream of the Facility s point of withdrawal. Patterns and trends in conductivity will be evaluated at the Peace River at Arcadia and the major downstream tributaries (Horse and Joshua Creeks). Potential dry season trends in conductivity immediately upstream of the Facility using fixed station and continuous recorder monitoring data will be evaluated and summarized. The results of these analyses will be evaluated relative to potential influences on Facility operations.

17 Chapter 7 Salinity/Flow/Withdrawal Relationships at Continuous Recorders Previous HBMP Mid-term (year three) and Summary (year five) Reports have developed both fixed location and spatial statistical models, which were used as predictive tools in assessing the magnitude of potential salinity changes due to both historic and potential maximum freshwater withdrawals under the existing permit conditions. The primary objective of this chapter will be to determine statistical relationships between flows, tide stage, and withdrawals at both the long-term USGS continuous gages, and the HBMP continuous recorders. The results of these analyses will be compared and contrasted with the results of other previous salinity models, thus setting the stage for Chapter 8. General characteristics of the data will be summarized describing differences among the data from the continuous recorders, including: 1. Period-of-record 2. Tidal variations 3. Frequency distribution of salinity values (ranges of daily and seasonal variability under differing flow conditions) Updated and new statistical models of surface and near bottom salinity for each of the three USGS continuous gages (freshwater inflows, stage, and withdrawals) will be developed. Updated and new statistical models of surface salinity at each of the eight HBMP continuous recorder locations using (freshwater inflows, estimated stage, and withdrawals) will be developed. These models will then be used to determine the effects of the predicted magnitude of historic permitted withdrawals. (The potential differences under the District s adopted minimum flows and levels (MFL) for the lower Peace River will be assessed in Chapter 8).

18 These results will then be compared with previous spatial and fixed salinity/flow model results from HBMP and District statistical modeling efforts. Chapter 8 Evaluation of Existing Withdrawal Schedule and Assessment of Effectiveness in Limiting Potential Impacts The primary objective of the analyses presented in this chapter will be to summarize and contrast the results of the recent hydrodynamic model developed by the District for use in establishing minimum flows and levels, with those presented above in Chapter 7. Existing empirical salinity models will be used to assess the effectiveness of the Authority's withdrawal schedule for preventing impacts to the natural resources of the Lower Peace River/ Upper Charlotte Harbor estuary. These results will be compared to withdrawal limits allowed by recently modified WUP diversions schedule. Data will be summarized using comparative univariate plots of actual field data, as well as that predicted under both the recent and newest permitted water withdrawal schedules. Summary tables will be included. Chapter 9 Evaluation of the Presence or Absence of Adverse Impacts and Appropriate Indicators The objectives of this section will be to provide a generalized discussion of the appropriate measurable criteria that can be linked to freshwater withdrawals and provide reasonable assurance for determining the potential for, or occurrence of, environmental change. The District permit condition specifically calls for the HBMP to assess if Facility withdrawals are adversely impacting the natural estuarine resources of the lower river. The primary objective of this chapter will be to describe the methodology and criteria used by the HBMP to determine if previous, existing and permitted Facility withdrawals have or are likely to cause significant environmental changes to the lower Peace River/upper Charlotte Harbor estuarine system. A corollary discussion would be the development of other potential indicators linked to freshwater inflows that would provide an overall assessment of the long-term health of the Lower Peace River/Upper Charlotte Harbor estuary. Update description of the processes for evaluating key water quality and biological estuarine indicators and determining potential significant environmental changes associated with both current and proposed future permitted withdrawals. Update discussion of management alternatives for addressing potential changes in status and trends in monitored HBMP program elements. Discuss and compare the findings of alternative methodologies utilized to model both historic and potential future effects of withdrawals on estuarine salinity structure.

19 Expand discussion of observed changes in HBMP indicators to periods of low flows. Summarize the observed occurrence of (or lack of) significant environmental changes due to Facility withdrawals. Chapter 10 Proposed Monitoring Design Modifications to the Existing Long-term HBMP Elements Based on the overall conclusions reached in the preceding chapters, this section will extend the discussions raised in previous Summary Reports, and recommend possible reductions and/or eliminations of specific parameters and elements within the current HBMP, as well as the potential implementation of new long-term study elements. Discuss criteria for including variables in the monitoring program. Recommend reduction/elimination/enhancement of HBMP elements based on previous analyses. Outline goals and scope of HBMP Scientific Panel suggested new HBMP study elements and/or special studies. Discuss possible future methods to enhance evaluation of potential changes in the health of the lower river estuarine system, used to assess the magnitude of observed changes due to Facility withdrawals relative to natural seasonal and long-term variability.